This type of appliance is well-known: inside a juice separating chamber, a pressing screw, typically bullet-shaped, is rotated by an ad hoc electric motor, the mechanical output of which is coupled to the base of the screw, while food, entering at the top of the chamber via an intake chute toward the bottom, is, under the action of the screw, gradually driven toward the bottom and pressed against the interface of the bottom of the chamber. The juice is collected for consumption by the user, while separately, the pressed food residue is discharged. The interest of this type of appliance lies in obtaining high-quality juice, while largely preserving its gustatory and organoleptic properties. Examples of this type of appliance are provided, inter alia, in EP 2,326,220.
One of the technical limitations of this type of appliance is the maximum size of the food that can be pressed. Indeed, in order for the pressing screw to be able to “catch” this food and begin to drive it downward to press it, it is necessary, for a given screw diameter, for this food to be small enough, the maximum size of this food typically having to be smaller than the largest radius of the pressing screw. The user is therefore quite frequently required to chop the food before placing it in the appliance. For example, the intake of a whole apple is impossible.
To bypass this difficulty, EP 2,326,220, through the embodiments of its FIGS. 1 to 5, proposed to arrange, between the outlet of the intake chute and a lower pressing part of the screw, a food fragmenting member, which consists of a cutting edge or a sharp blade, in the form of a helix portion, and which is securely carried by an upper part of the screw: due to the joint rotation of the upper and lower parts of the screw, this cutting edge or blade sweeps the outlet of the chute, such that the food leaving the outlet is cut into two slices. The implementation of such cutting of the food by the upper part of the pressing screw nevertheless poses practical difficulties. Indeed, considered alone, this cutting is done in the direction where it leads to the cut pieces of food being sent to the lower part of the screw in order for that lower part to press them. However, due to the screw pressing technique itself, the maximum quantity of food that can be “swallowed” and effectively pressed by the lower part of the screw is limited whereas, for the same rotational driving speed of the screw around itself, the maximum quantity of food that can be cut by the upper part of this screw is much larger for most foods. As a result, during use, the food cut by the upper part of the screw quickly saturates its lower part, which then rotates in a purée of food that is not completely pressed, while being incapable of “catching” the new pieces of cut food, since the latter are floating in the aforementioned purée. The appliance then becomes unusable and must be fully cleaned.
For its part, CN 204,218,617 proposes to arrange, at the apex of the pressing screw, a cutting tool which, by rotating around itself, cuts the food leaving the chute, in particular into slices, before that food reaches the pressing screw. This cutting tool is rotated around itself by a first shaft that is coaxial to but independent from a second shaft ensuring the rotational driving of the pressing screw around itself. The first shaft is directly coupled to the driving output of an electric motor, while the second shaft is also coupled to the driving output of that motor, but with a deceleration component inserted: the pressing screw is thus rotated x times less quickly than the cutting tool, with the aim of withdrawing the food introduced into the appliance in small slices that supply the inlet of the pressing screw. One then arrives at the same situation involving saturation risk situation as that cited above, this risk of saturation being more or less pronounced depending on the nature of the inserted food. The considered appliance therefore is also not satisfactory for all possible types of food.
It will be understood that to bypass this issue, the user may make sure only to introduce a small quantity of food at a time into the appliance and wait for it to be fully pressed before inserting a new small quantity. Such an approach is, however, unthinkable in the field of professional appliances.